Antennas are in the landing gear on the P4 series. OP replaced those also.
I’m assuming(not a good thing to do at times)by”GPS Module” the OP switched out the GPS puck that resides in the center of the upper shell. Not a fun job on the Phantom series.
“Several years” of storage? Is it possible that it was stored in an area that moisture could have been an issue? I’ve always thought it’s a good idea to test an aircraft prior to any update to determine how things work. Updates have their purpose but can also provide unwanted issues. Research is...
Some herd thinning. Aircraft, one high capacity battery, charger, props, and controller.
975.00 shipped (conus), PayPal fees on buyer. Additional pictures if needed via PM.